Negron appeared in four games with the Reds in 2012, but that is his only MLB experience. The 28-year-old was hitting .269/.328/.406 at Louisville this season.
Contreras appeared in three games out of the bullpen for the Reds, allowing one run in 4 1/3 innings.
Werth reached base three times in the win, the third time he has done so in his last five games. He went 2 for 3 with a walk, and both of his hits went for extra bases. Werth drove in one run in the first inning with a double, and added a solo home run in the seventh, finishing with two runs and two RBI.
Werth has raised his batting average nearly 15 points over the last seven games, and is now hitting .279/.364/.421 in 330 at-bats overall.
"He’s starting to swing the bat better," Ausmus said. "We were just talking about that in the coaches room. He’s been swinging the bat better, and I know he had a strong second half last year. We’re hoping he’s trending towards that again, because that would be a big boost to the bottom half of the lineup and the left side."
For the year, Avila is hitting .226 with six homers and 21 RBI in 212 at-bats.
Walker scored the Pirates only two runs of the game, as he came around each time he made it on base. Walker finished the game 2 for 4 with a double and a solo home run, his first since June 3.
Walker is hitting .279/.347/.448 with 12 home runs and 39 RBI in 77 games this season.
Abreu opened the game with a solo shot in the first inning, and ended up finishing the game 2 for 4 with one RBI and one run. It was his third home run in the last nine games, and gave him 28 for the season, to go with 70 RBI.
Abreu is hitting .284/.333/.627 in 306 at-bats through the first 78 games of his rookie season.
Over his last eight games, Machado has five homers, giving him nine this season in 234 at-bats.
Reimold, who went 2 for 4 with a pair of doubles Tuesday, followed that up with another 2-for-4 effort Wednesday. He had one double Wednesday, and drove in three runs, while adding a walk in an 8-7 loss.
Reimold was acquired by the Blue Jays after the Orioles waived him following a rehab assignment. Prior to this week, he had not played since May, 2013, due to neck problems.